Docusate sodium !
A stool softener: a detergent-like molecule that lets water and fat mix into hard stool so it passes with less straining.
Updated 2026-11-01
Also called: Dioctyl sodium sulfosuccinate, Docusate
Mechanism of action
Docusate is an anionic surfactant. It lowers the surface tension of the stool so water and fats can mix into it, and the stool becomes softer. It may also increase intestinal fluid and electrolyte secretion. Its laxative effect is mild, and in chronic constipation it adds little.
- Anionic surfactant lowers stool surface tension
- Water and fat mix into the stool and soften it
- Softer stool passes with less straining
Pharmacokinetics
- Onset and duration
- A bowel movement usually comes within 12 to 72 hours
Indications
- Short-term relief of occasional constipation and prevention of hard, dry stools Constipation and faecal impaction →
- Avoiding straining in heart disease, with haemorrhoids and in other conditions Haemorrhoids →
Adverse effects
Common
- Abdominal cramps
- Nausea
- Throat irritation with the oral liquid
Contraindications
- Abdominal pain, nausea or vomiting
- Use for more than a week without medical advice
Key interactions
- Mineral oil
- The label advises against combining them unless a doctor directs it
What is monitored
- Stool consistency and frequency
- Abdominal pain or vomiting
- Rectal bleeding or no bowel movement
Administration and safety
- Capsules are swallowed whole with a full glass of water, not split or chewed.
- The oral liquid is measured with its marked dropper and can be mixed with milk or juice to hide the bitter taste.
- Often given at bedtime.
Nursing care
- Check for abdominal pain, nausea or vomiting before giving it.
- Ask whether the patient uses mineral oil.
- Explain that it softens stool but does not stimulate the bowel; fluids and fibre still matter.
- Report rectal bleeding or lack of effect.
Pregnancy and breastfeeding
Usually acceptable in pregnancy and breastfeeding after checking with a clinician.
Test yourself
Think of the answer, then tap the question to see it.
How does docusate soften stool?
As an anionic surfactant it lowers the stool's surface tension, letting water and fat mix into it.
Which patients benefit most from a stool softener?
Those who should avoid straining, for example with heart disease or haemorrhoids.
Which product should not be combined with docusate unless a doctor directs it?
Mineral oil.
Related drugs
Related conditions
← Back to the class: Laxatives
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - DOCUSATE SODIUM capsule, liquid filled (DailyMed (U.S. National Library of Medicine), 2026); Stool Softeners: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2024); Docusate: a laxative medicine to treat constipation - NHS (NHS (National Health Service, UK), 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 54 (McGraw Hill, 2023).
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Representative model, for educational purposes only.